Gmail Contact Sync question...

Hi guys just synced my iphone contacts with Gmail contacts and I was wondering if the sync for the contacts is pushed based like the emails? or does it check it at predetermined times (ie. every 15 minutes). I'm asking because I don't want the contacts sync to eat up my data plan. Thanks.

MacRumors attracts a broad audience
of both consumers and professionals interested in
the latest technologies and products. We also boast an active community focused on
purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms.